Electronic shutter for photographic camera

ABSTRACT

In order that a designed specific exposure time, for example, one-one hundred twenty-fifths of a second, may be obtained automatically in case the electronic exposure time control means has become disabled due to causes such as dissipated battery, there is provided an electronic shutter for photographic camera comprising a hook lever adapted to anchor the armature lever for a while only when the electronic exposure time control means fails to work at the time the shutter is released, and a cam member for releasing said anchored state. This electronic shutter contains a flash light means which is rendered ready to being operative when the electronic exposure time control means is switched over to the inoperative state.

Shimizu Dec. 11, 1973 ELECTRONIC SHUTTER FOR PHOTOGRAPHIC CAMERAInventor: Munetaka Shimizu, Tokyo, Japan Assignee: Kabushiki KaishaKoparu,

ltabashi-ku, Japan Filed: May 19, 1972 App]. No.: 255,085

Foreign Application Priority Data May 25, 1971 Japan 46/42005 (utilitymodel) U.S. Cl. 95/53 EB Int. Cl. G03!) 9/58 Field of Search 95/10 CT,53 EB References Cited UNITED STATES PATENTS Primary Examiner-Samuel S.Matthews Assistant Examiner-Michael L. Gellner Attorney.lohn W. Malleyet al.

[57] ABSTRACT In order that a designed specific exposure time, forexample, one-one hundred twenty-fifths of a second, may be obtainedautomatically in case the electronic exposure time control means hasbecome disabled due to causes such as dissipated battery, there isprovided an electronic shutter for photographic camera comprising a hooklever adapted to anchor the armature lever for a while only when theelectronic exposure time control means fails to work at the time theshutter is released, and a cam member for releasing said anchored state.This electronic shutter contains a flash light means which is renderedready to being operative when the electronic exposure time control meansis switched over to the inoperative state.

2 Claims, 2 Drawing Figures PATENTEDMI: 1 1 ma SHEET 1 EF FIG.

ELECTRONIC SHUTTER FOR PHOTOGRAPHIC CAMERA BACKGROUND OF THEINVENTION 1. Field of the Invention The present invention is concernedwith an electronic shutter for photographic camera, and moreparticularly it pertains to means for opening and closing the shutterblades.

2. Description of the Prior Art Generally, in an electronic shutterarranged so that the exposure time is controlled electronically, theelectronic exposure time control means which is assigned to determinethe required exposure time will become disabled when the battery isconsumed excessively. Under such a condition, the shutter is able tocontrol only a certain single exposure time which is determined solelyby the mechanical condition under which the shutter is constructed.Usually, this certain single exposure time is either one five-hundredthor one onethousandth of a second, both of which is outside those limitsof exposure time which are most often utilized in ordinaryphotographing. For this reason, under such a situation that the batteryhas become dissipated to an excessive degree and that a new set ofbattery for replacement is not on hand, it will become practicallyimpossible to use the camera.

Also, when it is intended to conduct a flash light photographing by theuse of an electronic shutter of the aforesaid type in a darkenvironment, the abovementioned electronic exposure time control meansbecause of the fact that it contains an element such as aphotoconductive cell having a delayed response to the changes inbrightness of light is unable to behave to meet these changes inbrightness of the flash light. As a consequence, there may arise theinconvenience that the shutter blades remain opened. In order to preventthis condition from taking place, there has been proposed a shutterarrangement in which the element such as said photoconductive cell isswitched over to a specific fixed resistor at the time of taking a flashlight photography. However, such an improved known device had thedrawbacks that not only the mechanism per se become excessivelyintricate but also in actual use the camera had to be operated with agreat complexity.

SUMMARY OF THE INVENTION It is, therefore, a primary object of thepresent invention to provide an electronic shutter having a shutterblade opening and closing means which, when the electronic exposure timecontrol means becomes disabled due to reasons such as dissipatedbattery, is automatically switched over to a mechanical mode ofoperation to give a designed specific exposure time which may be, forexample, one one-hundred twenty-fifth of a second.

Another object of the present invention is to provide an electronicshutter which can be used very satisfactorily in flash lightphotographing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of the essentialportion, in a cocked position, of an example of the shutter bladeopening and closing means according to the present invention; and

FIG. 2 is a circuit diagram showing an example of the exposure timecontrol circuit and the flash light means which are applied to the meansshown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGS. 1 and 2,reference numeral 1 represents a control cam rotatably supported on ashaft 2 and provided with a hook la and a cam face 1b whose diameterincreases progressively as it turns clockwise. This control cam 1 isurged to rotate counter-clockwise. Numeral 3 represents a cam memberhaving a cam face 3a and provided concentrically and integrally withsaid control cam l. Numeral 4 represents a release lever swingablymounted on a shaft 5 and having a bent portion 4a which is brought intoengagement with the hook la when the shutter is cocked. Numeral 6represents a spring for urging the release lever 4 to rotatecounter-clockwise. Numeral 7 represents a shutter blade opening memberpivotably supported on a shaft 8 and having a pin 7a. Numeral 9represents a spring for urging the shutter blade opening member 7 torotate clockwise. Numeral 10 represents a stopper for limiting theclockwise movement of the shutter blade opening member 7. Numeral l1represents a lock lever swingably supported on a shaft 12 and having abent portion 11a for locking the shutter blade opening member 7 at itscocked position when the shutter is cooked. Numeral 13 represents aspring for rging the lock lever 1 1 to rotate clockwise. Numeral 14represents a stopper for limiting the clockwise movement of the locklever 11. Numeral 15 represents an actuating member attached integrallyto the control cam l and assigned to urge the lock lever 11 to rotatecounter-clockwise in the final stage of the counterclockwise movement ofsaid control cam l. Numeral 16 represents an electromagnet which iscontrolled of its conducting time by the exposure time control circuitwhich will be described later. Numeral 17 represents an armature leverpivotally supported on a shaft 18 and having at the end of one of itsarms a pole-contacting portion 17a capable of contacting, in abuttingfashion, the magnetic pole of the electromagnet 16, and having at theend of the other of the arms a bent portion 17b. Numeral 19 represents aspring for urging the armature lever 17 to rotate counter-clockwise.Numeral 20 represents a holding lever swingably mounted on the shaft 18and having at the end of one of its arms a bent portion 20a which isbrought into contact with the polecontacting portion 17a of the armaturelever 17 and having at the end of the other of the anns a roller 20bwhich is adapted to contact, while rotating, the cam face lb of thecontrol cam 1. Numeral 21 represents a spring for urging the holdinglever 20 to rotate clockwise. Numeral 22 represents a spring providedbetween the armature lever 17 and the holding lever 20. Numeral 23represents a hook lever pivotably supported on a shaft 24 and having atits foremost end portion a hook 23a which is engageable with the bentportion 17b of the armature lever 17 and having a bent portion 23bformed at its intermediate portion. Numeral 25 represents a controllever swingably supported on the shaft 24 and having an arm the end 25aof which is in contact with the cam face 3a of the cam member 3 andhaving another arm 25b protruding into the path of movement of the pin7a of the shutter blade opening member 7 and having an intermediateportion which engages the bent portion 23b of the hook lever 23. Numeral26 represents a spring for urging the control lever to rotatecounter-clockwise. Numeral 27 represents a spring provided between thehook lever 23 and the control lever 25 in such a way that these twomembers pull each other. Numeral 28 represents a shutter blade closingmember swingably supported on a shaft 29 and urged by a spring 30 torotate clockwise. Numeral 31 represents a stopper for limiting theclockwise rotation of the shutter blade closing member 28. Numeral 32represents a lock lever pivotably supported on a shaft 33 and urged torotate clockwise and having at the end of one of its arms a bent portion32a for anchoring, at the cocked position of the shutter, the shutterblade closing member 28 in its cocked position, and having at the end ofthe other of its arms a pin 32b which protrudes into the path ofmovement of the armature lever 17. Numeral 34 represents a stopper forlimiting the clockwise rotation of the lock lever 32.

FIG. 2 shows an example of known exposure time control circuits. In thisdrawing, numeral 35 represents a photoconductive element. Numeral 36represents a capacitor which, together with said photoconductive element35, forms a CR delay circuit. Numeral 37 represents a switch foractuating this CR delay circuit. Numerals 38, 39 and 40 representtransistors. Numeral 41 represents a power switch. Numeral 42 representsa battery used to serve as the power source. The electromagnet 16 isinserted in the collector circuit of the transistor 40. Numeral 43represents a known flash light means which may be either detachablymounted on the camera body or housed within the camera body. Numeral 44represents a flash bulb. Numeral 45 represents a capacitor. Numeral 46represents a synchronized switch which is closed by the shutter bladeopening member 7 when the latter is released. Numeral 47 represents achangeover switch.

In the arrangement described above, the relative positions of thearmature lever 17 and the hook lever 23, and the magnitudes of theforces of the springs 19 and 26 are selected as follows. That is to say,the force of the spring 19 is weaker than the attracting force of theelectromagnet 16 and also is weaker than the force of the spring 21.Also, the relation of engagement of the armature lever 17 with the hooklever 23 is such that these two levers are relased of their engagementwhen the hook lever 23 is caused to be rotatd counterclockwise from itsposition illustrated via the control lever 25 when the armature lever 17is in the state of being attracted to the electromagnet 16. as shown,and that, in the condition where the armature lever 17 is not attractedto the electromagnet 16 and where the armature lever 17 is caused to berotated counterclockwise from its position illustrated by the spring 19before the hook lever 23 is rotated counter-clockwise from its positionillustrated, the engagement between said armature lever 17 and the hooklever 23 is maintained as it is by virture of a part of thecounterclockwise rotation force of the armature lever 17. Accordingly,the relative positions of the cam faces 1b and 3a are selected in such away that when the control cam l is rotated counter-clockwise from itsposition illustrated, there first will occur a counter-clockwiserotation of the holding lever 20 caused by the cam face lb. On the otherhand, the control cam l is arranged so that it opens the switch 37 inthe final stage of its counter-clockwise movement to actuate the CRdelay circuit and that thereafter it is brought to a halt by a stoppernot shown.

Next, description will be made on the actions of the apparatus ofthepresent invention, based on the assumption that the changeover switch47 has been switched over to the terminal a side as shown.

The release lever 4 is rotated clockwise in the cocked state of theshutter. whereupon, first the power switch 41 is closed to render theexposure time control circuit shown in FIG. 2 operative. As aconsequence, the transistor 40 is rendered conductive so that theelectromagnet 16 is energized. As a result, the armature lever 17 isheld in its state of being attracted to the electromagnet 16 as shown.Thereafter, as the bent portion 4a of the release lever 4 is disengagedfrom the hook la, the control cam 1, together with the cam member 3 andthe actuating member 15, is rotated counter-clockwise by a drive springnot shown. Subsequently, first the holding lever 20 is caused to berotated counter-clockwise by the cam face lb so that the bent portion20a of this holding lever 20 is caused to move away from thepolecontacting portion 17a of the armature lever 17, and then thecontrol lever 25 is released of its anchored state by the cam member 3so that the hook lever 23 is rotated counter-clockwise with thecounterclockwise movement of said control lever 25, thereby causing thehook 23a to disengage from the bent portion 171) of the armature lever17. Thus, in the final stage of the counter-clockwise movement of thecontrol cam 1, the lock lever 11 is rotated counterclockwise by theactuating member 15, causing the bent portion 11a of the lock lever 11to detach from its position of engagement with the shutter blade openingmember 7. At the same time therewith, the switch 37 is opened. As aconsequence, the shutter blade opening member 7 is rotated clockwise toopen the shutter blades not shown. At the same time therewith, the CRdelay circuit is actuated to start the counting of the exposure time. Inthis way, when the voltage across the terminals of the capacitor 36which is charged through the photoconductive element 35 whose resistancevalue varies with the brightness of the object to be photographed gainsthe predetermined value, the transistor 38 is rendered conductive. As aresult, the transistor 40 is rendered to the cut-off state, causing theelectromagnet 16 to be de-energized. Since this electromagnet 16 is thusdeprived of its attracting force, the armature lever 17 is caused to berotated counter-clockwise from its position illustrated, causing thelock lever 32 to be rotated counter-clockwise. Accordingly, the bentportion 32a of this lock lever 32 is moved away from its position ofengagement with the shutter blade closing member 28. As a consequence,this shutter blade closing member 28 is rotated clockwise to close theshutter blades not shown. With this, one normal exposing actioncompletes. During this action, the power switch 41 is arranged so thatonce it is closed by the clockwise rotation of the release lever 4, thispower switch 41 will be held in its closed state continuously till theopening and closing actions of the shutter blades come to an end.

Next, description will be directed to an instance in which the battery42 has dissipated to such an extent that even when the power switch 41is closed, there is produced in the electromagnet 16 no magnetic forceof the predetermined magnitude. In such a condition, upon thecounter-clockwise rotation of the control cam 1 caused by the release ofthe shutter, the armature lever 17 will tend to rotate counter-clockwiseby following the counter-clockwise movement of the holding lever 20.However, the bent portion 17b of the armature lever 17 is in firmengagement with the hook 23a of the hook lever 23 by virture of a partof the force of counter-clockwise rotation of this armature lever 17, sothat even after the suppression applied to the hook lever 23 by the camface 3a is released, both the control lever 25 and the hook 23 are heldin their state illustrated, against the force of their counter-clockwisemovement which is caused by the spring 26. Accordingly, the armaturelever 17 is first held in its state shown and thereafter the control cam1 is rotated counter-clockwise up to its final position to cause thelock lever 11 to be rotated counter-clockwise by the actuating member15. As a result, the shutter blade opening member 7 is rotated clockwiseso that the shutter blades are opened, and the control lever 25 iscoercively rotated counter-clockwise by the pin 7a. As a consequence,the engagement between the hook lever 23 and the armature lever 17 isreleased for the first time. In this way, the armature lever 17 rotatescounter-clockwise. Thereafter, the shutter blades are closed in theorder as described above. As will be clear from the foregoing statement,the time interval from the time the shutter blades are opened till thetime they are closed may be set to, for example, one one-hundedtwenty-fifth of a second, by appropriately selecting the depth ofengagement between the armature lever 17 and the hook lever 23 and alsothe distance between the control lever 25 and the pin 7a of the shutterblade opening member 7 which is produced when these two members are inthe state of having parted away from each other. The cocking of theshutter is performed by first rotating the control cam 1 clockwise up tothe position at which the hook 1a is brought into engagement with thebent portion4a of the release lever 4, and along therewith by rotatingcounter-clockwise both the shutter blade opening member 7 and theshutter blade closing member 28 simultaneously up to the position atwhich these two members are brought into engagement with the lock lever11 and 32, respectively.

Description has been made with respect to the mode of operation wherethe changeover switch 47 has been switched over to the terminal a side.By switching this changeover switch 47 to the terminal b side, the flashlight means 43 is connected to the battery 42 so that the flash lightmeans 43 is rendered to a state ready for performance. It should benoted with respect to this latter mode of operation that the exposuretime control circuit is rendered inoperative and that, accordingly, theshutter blade opening and closing means will behave in the same fashionas that caused where the battery 42 has dissipated. Accordingly, whenthe shutter blade opening member 7 is rotated clockwise as a result of ashutter release operation as described previously, and when accordinglythe shutter blades are opened, the synchronized switch 46 is closed sothat the flash bulb 44 is lighted up and thus a flash lightphotographing is performed. As stated above, according to the presentinvention, it will be understood that by a mere switching-over of thechangeover switch 47, the flash light means is rendered to the stateready for performance and the shutter is rendered automatically to thestate suitable for a flash light photoraphing.

In the embodiment described above, the shutter blades are opened andclosed by rotating both the shutter blade opening member 7 and theshutter blade closing member 28 in the same direction. It is alsopossible to modify the mechanism, within the scope of the presentinvention, so that the shutter blades are opened and closed by arrangingthese two members 7 and 28 to rotate in the opposite directions andarranging them to associate with a single sector ring or like means andby causing said sector ring or like means to make reciprocatingmovements at the time the shutter is released.

I claim:

1. An electronic shutter for photographic camera, comprising an exposuretimecontrol circuit, a battery connected to said exposure time controlcircuit, an electromagnet connected to said exposure time controlcircuit, an armature lever having at one end thereof a pole-contactingportion facing the magnetic pole of said electromagnet, a holding leverprovided adjacent to said armature lever and arranged so as to urge saidpole-contacting portion against the magnetic pole of said electromagnet,a control cam member having a cam member provided thereon and having acam portion engageable with said holding lever, a shutter blade openingmember provided adjacent to said control cam member and arranged so asto be released by said control cam member in the final stage of movementof said control cam member, a shutter blade closing member providedadjacent to said armature lever and arranged so as to be released bysaid armature lever as the latter moves, a hook lever provided adjacentto said control cam member and having at one end thereof a hook portionengageable with said armature lever, and a control lever carried by saidhook lever and having two arms engageable with said cam member and saidshutter blade opening member, respectively, said electronic shutterbeing operative so that upon the shutter release operation, saidarmature lever is anchored by said hook lever only when said armaturelever tends to move without being attracted to said electromagnet andheld there, and that this anchored state is released by the shutterblade opening member as this member moves.

2. An electronic shutter for photographic camera according to claim 1,in which said electronic shutter comprises a changeover switch havingone end connected to said battery and a flash light means having one endconnected to said exposed time control circuit, and is arranged so thatsaid exposure time control circuit and said flash light means may beused alternatively by swtiching over said changeover switch.

1. An electronic shutter for photographic camera, comprising an exposuretime control circuit, a battery connected to said exposure time controlcircuit, an electromagnet connected to said exposure time controlcircuit, an armature lever having at one end thereof a pole-contactingportion facing the magnetic pole of said electromagnet, a holding leverprovided adjacent to said armature lever and arranged so as to urge saidpole-contacting portion against the magnetic pole of said electromagnet,a control cam member having a cam member provided thereon and having acam portion engageable with said holding lever, a shutter blade openingmember provided adjacent to said control cam member and arranged so asto be released by said control cam member in the final stage of movementof said control cam member, a shutter blade closing member providedadjacent to said armature lever and arranged so as to be released bysaid armature lever as the latter moves, a hook lever provided adjacentto said control cam member and having at one end thereof a hook portionengageable with said armature lever, and a control lever carried by saidhook lever and having two arms engageable with said cam member and saidshutter blade opening member, respectively, said electronic shutterbeing operative so that upon the shutter release operation, saidarmature lever is anchored by said hook lever only when said armaturelever tends to move without being attracted to said electromagnet andheld there, and that this anchored state is released by the shutterblade opening member as this member moves.
 2. An electronic shutter forphotographic camera according to claim 1, in which said electronicshutter comprises a changeover switch having one end connected to saidbattery and a flash light means having one end connected to said exposedtime control circuit, and is arranged so that said exposure time controlcircuit and said flash light means may be used alternatively byswtiching over said changeover switch.